Tire suggestions for 8 x 17 style 5 on 85 M635

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Pat_M635csi
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Tire suggestions for 8 x 17 style 5 on 85 M635

Post by Pat_M635csi »

So I upgraded the front brakes to the Brembro e31 set up on my 85 m635. This of course led to the need for 17" wheels to accommodate them, which given the original 3 piece TRX BBS basketweaves were a tad too small, I opted for the 17" e39 style 5s. They came wrapped with some old Potenza 235/45-17 which seem a bit wide and tend to tram. I am wondering if I can drop down to 225/50 or 225/55? at least on the fronts could go a bit wider on the rears I believe. Thoughts?
1985 M635CSI M88/3
1997 Z3 2.8
2010 535xi Touring w/Dinan Stage 3 upgrade
following were sold but not forgotten
2000 540it
1972 3.0CS Polaris
1972 3.0CSI Polaris
1986 735i 5sp
1983 733i
1969 2000 tilux
1972 2002 tii
1973 2002
ron
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Post by ron »

Are your style 5s staggered width? I have them 8" front and 9" rear with 235/45 and 265/40 without any problems. These sizes are near enough the original fitment rolling radii.

Don't forget if you have more than 10% difference front/rear rolling radii you will trigger the ABS.
They are ALWAYS rustier than you thought!!!!!!
'85 M #228
'87 M #367
'88 High line.
'10 X5
‘84 Alfasud 1.5 ti
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Pat_M635csi
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Post by Pat_M635csi »

Not staggered 8 x 17 all around. Had not known about the ABS trigger thanks for that. What type of tires are you using
1985 M635CSI M88/3
1997 Z3 2.8
2010 535xi Touring w/Dinan Stage 3 upgrade
following were sold but not forgotten
2000 540it
1972 3.0CS Polaris
1972 3.0CSI Polaris
1986 735i 5sp
1983 733i
1969 2000 tilux
1972 2002 tii
1973 2002
ron
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Posts: 4569
Joined: Sat Jul 10, 2004 11:35 am
Location: South Wales U.K.

Post by ron »

I have Falken FK 451s on the 17" and I have a set of Falken FK 452s on an 18" set. They seem excellent wet or dry.
They are ALWAYS rustier than you thought!!!!!!
'85 M #228
'87 M #367
'88 High line.
'10 X5
‘84 Alfasud 1.5 ti
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tschultz
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Post by tschultz »

225/45/R17 seems to be a good size for an 8" wheel :D
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'79 635CSi Revival
'80 635CSi
'83 633CSi Callaway Turbo continued as 1988 535is Turbo
SOLD: '81 635CSi/A
GazM3
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Post by GazM3 »

Tyres are very subjective. 235/45 seems about right or 225/45.

The tam lining may be an alignment issue or worn tyres /worn suspension bushes may contribute also

I run continental sport contact3 and find them good all rounder with enough dry grip to be fun and pretty safe in the wet. A few of my fiends have one for Michelin pilot super sport and rave about them. When I get my m3 back in the road this is what tyres I'll be putting on
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84 E24 M635csi
90 E34 M5 3.6
94 E34 540i/6 SC E85
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Pat_M635csi
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225/45 or 225/50 17 on 8 inch wide rim?

Post by Pat_M635csi »

If you go to 225 do you need to step up to 50 series to keep the overall radius the same?
1985 M635CSI M88/3
1997 Z3 2.8
2010 535xi Touring w/Dinan Stage 3 upgrade
following were sold but not forgotten
2000 540it
1972 3.0CS Polaris
1972 3.0CSI Polaris
1986 735i 5sp
1983 733i
1969 2000 tilux
1972 2002 tii
1973 2002
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tschultz
Posts: 2515
Joined: Wed Jul 07, 2010 10:54 pm
Location: Colorado
Contact:

Re: 225/45 or 225/50 17 on 8 inch wide rim?

Post by tschultz »

Pat_M635csi wrote:If you go to 225 do you need to step up to 50 series to keep the overall radius the same?
225/50/R16 is comparable to 225/45/R17 within a couple mm's. So no, any bigger means you will have taller sidewall the factory intended size.

Play around here:
http://www.rimsntires.com/specspro.jsp
http://www.Drive4Corners.com
Image
'79 635CSi Revival
'80 635CSi
'83 633CSi Callaway Turbo continued as 1988 535is Turbo
SOLD: '81 635CSi/A
User avatar
Pat_M635csi
Posts: 50
Joined: Wed Dec 11, 2013 9:28 pm
Location: Boston

How about 235/45-17 F 265/40-17 R?

Post by Pat_M635csi »

Has anyone tried using 8" x 17 all around but with different rears?

235/45-17
265/40-17
1985 M635CSI M88/3
1997 Z3 2.8
2010 535xi Touring w/Dinan Stage 3 upgrade
following were sold but not forgotten
2000 540it
1972 3.0CS Polaris
1972 3.0CSI Polaris
1986 735i 5sp
1983 733i
1969 2000 tilux
1972 2002 tii
1973 2002
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jps635
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Post by jps635 »

265's would be too wide for an 8" rim, you would need 9's as per Ron.

Regarding tyres, read the tyre tests and decide what y0u want / can afford from there. Generally the more expensive the tyre, the gippier they are (better). Tyre life is not so important unless you're burning up the miles, as they can age harden if not used a lot.

I've found Goodyear Eagle F1's to be both grippy and more compliant with hard suspension (and quieter) than Potenzas.

Chris
'85 635csi JPS (RA2-66)
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Pat_M635csi
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235/45-17 sounds like a decent set up

Post by Pat_M635csi »

235/45-17 sounds like a decent set up. Since I barely put 3k a year on the car and only driven in the summer - I will opt for something sticky.
1985 M635CSI M88/3
1997 Z3 2.8
2010 535xi Touring w/Dinan Stage 3 upgrade
following were sold but not forgotten
2000 540it
1972 3.0CS Polaris
1972 3.0CSI Polaris
1986 735i 5sp
1983 733i
1969 2000 tilux
1972 2002 tii
1973 2002
User avatar
Pat_M635csi
Posts: 50
Joined: Wed Dec 11, 2013 9:28 pm
Location: Boston

245/40-17 Mike Millers suggestion

Post by Pat_M635csi »

So I was looking back on some of Mike Millers suggestions and he indicated that to replace the stock TRX 240/45-415 24.5" O.D. So he suggested 245/40/17 24.7" or 235/45-17 24.7" O.D.

If those O.D. are correct then maybe I could run that 235/45-17 on the front and 240/40-17 rears
1985 M635CSI M88/3
1997 Z3 2.8
2010 535xi Touring w/Dinan Stage 3 upgrade
following were sold but not forgotten
2000 540it
1972 3.0CS Polaris
1972 3.0CSI Polaris
1986 735i 5sp
1983 733i
1969 2000 tilux
1972 2002 tii
1973 2002
bkats

Post by bkats »

I run 235/45 Continental Extremecontact DW's on my 17" e39 style 5's. I run 17x8 all around and found the continentals to be really quiet, something we can all appreciate as our cars tend to generate small hurricanes at speed anyways.

The continentals seemed to be the best balance of comfort, performance, and price. My '89 is my daily so I wanted something reasonably affordable for the 8-10k I put on each year. I also run a full-size spare so that 5th tire adds some cost for me.
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